Telecommunication subracks are equipped with power feeding boards for securing power feed to the backplane for further distribution to the cards and for supplying power to cooling fans, etc. A known solution is to provide vertically arranged power feeding boards in the card cage, at each side of the subrack, left and right, to achieve a redundant feeding.
Usually two separate fan units are arranged to cool the subrack, one at the top and one at the bottom to achieve a redundant cooling. The power is provided from the power feeding boards to each fan unit via power cables originating from the front of the power feeding board, taking up connector space on the front of the power feeding boards. Since more and more power is needed to feed subracks, the connector space at the front of the power feeding boards as well as the area for components on the power feeding boards is becoming a rare asset. The power cables can also originate from an external power source and be directly connected to the fan units.
Another solution is to provide the power feeding boards further back in the subrack. That way the problem with cables in front of the subrack is diminished. However, provision of a power feeding board behind the front of the subrack, for example from the back of the subrack, makes it less accessible and, consequently, more difficult to connect components to the power feeding board. Further, if the power feeding board is large, the shape of other, adjacent components must be modified in order to fit in the subrack.
It is therefore a desire for a subrack with a power feeding board of sufficient size and number of connectors to meet the ever increasing power need, at the same time as the power feeding board is easily accessible and replaceable.